Golf clubhead with a corner-back system of weight distribution

Abstract

A golf clubhead includes a lower density body with a corner-back system of higher density weights. In its basic form the corner-back system has a weight in each corner of the golf clubhead. In other forms the weights may be variously joined, one or more may be deleted, or there may be more than four. The basic form of the corner-back system may be viewed as having a double split of a head weight. The first split yields a toe wieght and a heel weight to reduce twisting along the vertical twist axis. The second split yields upper and lower toe weights and upper and lower heel weights to reduce twisting along the horizontal loft axis. The corner-back system offers a designer an opportunity to optimize moments of inertia along both the vertical twist and the horizontal loft axes. The degree of optimization along either axis is a matter of choice. The quantization of the weights into a double split arises because of constraints by the clubhead's center of mass. The center of mass should be neither too high on nor too far behind the striking face. Mass-bit computations were performed on two near-clubheads. The first had a lower density aluminum body and a corner-back system of higher density tunsten weights. The second had a corner-back configuration with body and weights all of moderate density beryllium copper. The A1-W system had a 40 percent larger moment across the vertical twist axis and a 98 percent larger moment across the horizontal loft axis than the BeCu system. Thus, a head with a lower density body and a corner-back system of higher density weights may be regarded as more inertially efficient than a head in a simple corner-back configuration with body and weights all of one moderate density.

What is claimed is: 
     
       1. A golf clubhead comprising: a. a body of a predetermined lower density;   b. a head weight means comprising at least one head weight serving as inertial weight for said clubhead whereby each said head weight is of a predetermined higher density greater than said predetermined lower density of said body; p1 c. a toe and a heel, a front and a back, and a top and a sole with a ball striking surface toward said front;   d. a binding means to attach said head weight means to said clubhead;   e. a fastening means to affix a shaft between said heel and said toe;   g. a toe section of said clubhead extending one-half the length of said clubhead from an extreme of said toe toward said heel to a central boundary defined by a vertical cut-plane positioned perpendicularly to the length line of said clubhead;   h. a toe weight means comprising at least one toe weight of the portion of said head weight means in said toe section serving as inertial weight for said toe section;   i. a modified toe weight distribution to position between said ball striking surface toward said front and said back: (i) a first substantial percentage of said toe weight means as an increased upper concentration of mass in a predetermined fixed upper location adjacent said top and said toe, and a second substantial percentage of said toe weight means as an increased lower concentration of mass in a predetermined fixed lower location adjacent said sole and said toe;   (ii) a middle volume directly between said increased upper and lower concentrations of mass having a decreased middle concentration of said toe weight means substantially less concentrated than each of said increased upper and lower concentrations to substantially separate said increased upper concentration from said increased lower concentration; and   (iii) an upper central volume directly between said increased upper concentration and said central boundary of said toe section having a decreased upper central concentration of said toe weight means substantially less concentrated than said increased upper concentration tending to separate said increased upper concentration from said central boundary; whereby   j. polar moments of inertia of said clubhead are enhanced.     
     
     
       2. The golf clubhead of claim 1 having a ratio of masses between the mass of said toe weight means and the complete mass of said toe section of at least 0.10; and having a ratio of densities between the density of said toe weight means and the density of said body in said toe section of at least 1.20. 
     
     
       3. The golf clubhead of claim 2 whereby said ratio masses is at least 0.50; and said ratio of densities is as least 4.0. 
     
     
       4. The golf clubhead of claim 2 whereby the density of the material of said toe weight means is at least 11.5 grams per cubic centimeter with a content of tungsten of at least 10 percent by weight. 
     
     
       5. The golf clubhead of claim 2 whereby: a. said first substantial percentage of said toe weight means as said increased upper concentration of mass and said second substantial percentage of said toe weight means as said increased lower concentration of mass together represent one hundred percent of the mass of said toe weight means;   b. said increased upper concentration of mass is completely separated from said increased lower concentration of mass; and   c. the central extent of said increased upper concentration toward said central boundary is less than one-half the length of said clubhead from the extreme of said toe.   
     
     
       6. The golf clubhead of claim 5 whereby the length, width, and height of said increased upper concentration of mass are between about one-twentieth to one-third the length of said clubhead, one-tenth to nine-tenths the width of said clubhead, and one-twentieth to one-third the height of said clubhead, respectively. 
     
     
       7. The golf clubhead of claim 6 whereby both the length and the width of said increased upper concentration are greater than the height of said increased upper concentration. 
     
     
       8. A golf clubhead comprising: a. a body of a predetermined lower density;   b. a head weight means comprising at least one head weight serving as inertial weight for said clubhead whereby each said head weight is of a predetermined higher density greater than said predetermined lower density of said body;   c. a toe and a heel, a front and a back, and a top and a sole with a ball striking surface toward said front;   d. a binding means to attach said head weight means to said clubhead;   e. a fastening means to affix a shaft between said heel and said toe;   g. a toe section of said clubhead extending one-half the length of said clubhead from an extreme of said toe toward said heel to a central boundary defined by a vertical cut-plane positioned perpendicularly to the length line of said clubhead;   h. a toe weight means comprising at least one toe weight of the portion of said head weight means in said toe section serving as inertial weight for said toe section;   i. an upper toe section extending upward and a lower toe section extending downward, respectively, from a horizontal boundary in said toe section defined by a horizontal cut-plane positioned one-half the height of said clubhead from an extreme of said top of said clubhead;   j. an upper toe weight means comprising at least one upper toe weight of the portion of said toe weight means in said upper toe section serving as inertial weight for said upper toe section, and a lower toe weight means comprising at least one lower toe weight of the portion of said toe weight means in said lower toe section serving as inertial weight for said lower toe section;   k. a modified sectional weight distribution means to position between said ball striking surface toward said front and said back; (i) a substantial percentage of said upper toe weight means as an increased upper concentration of mass in a predetermined fixed upper location adjacent said top and said toe, and a substantial percentage of said lower toe weight means as an increased lower concentration of mass in a predetermined fixed lower location adjacent said sole and said toe;   (ii) a middle volume directly between said increased upper and lower concentrations having a decreased middle concentration of said toe weight means substantially less concentrated than each of said increased upper and lower concentrations to substantially separate said increased upper concentration from said increased lower concentration; and   (iii) an upper central volume directly between said increased upper concentration and said central boundary of said toe section having a decreased upper central concentration of said toe weight means substantially less concentrated than said increased upper concentration tending to separate said increased upper concentration from said central boundary; whereby     j. polar moments of inertia of said clubhead are enhanced.   
     
     
       9. The golf clubhead of claim 8 having a ratio of masses between the mass of said toe weight means and the complete mass of said toe section of at least 0.10; and having a ratio of densities between the density of said toe weight means and the density of said body in said toe section of at least 1.20. 
     
     
       10. The golf clubhead of claim 9 whereby said ratio of masses is at least 0.50; and said ratio of densities is at least 4.0. 
     
     
       11. The golf clubhead of claim 9 whereby the density of the material of said toe weight means is at least 11.5 grams per cubic centimeter with a content of tungsten of at least 10 percent by weight. 
     
     
       12. The golf clubhead of claim 9 whereby the mass of said upper toe weight means is less than the mass of said lower toe weight means to control the vertical location of the center of mass of said clubhead. 
     
     
       13. The golf clubhead of claim 12 whereby the density of said upper toe weight means is less than the density of said lower toe weight means to control the vertical location of the center of mass of said clubhead. 
     
     
       14. The golf clubhead of claim 9 whereby: a. the far extent toward said toe of said increased upper concentration of said upper toe weight means and the far extent toward said toe of said increased lower concentration of said lower toe weight means are each positioned within about one-fourth the length of said clubhead from the extreme of said toe;   b. the upper extent of said increased upper concentration toward said top and the lower extent of said increased lower concentration toward said sole are positioned within about one-fourth the height of said clubhead from the extreme of said top and an extreme of said sole of said clubhead, respectively;   c. said substantial percentage of said upper toe weight means as said increased upper concentration and said substantial percentage of said lower toe weight means as said increased lower concentration together represent one hundred percent of the mass of said toe weight means;   d. said increased upper concentration of mass is completely separated from said increased lower concentration of mass, and the lower extent of said increased upper concentration of mass toward said horizontal boundary is less than one-half of the height of said clubhead from the extreme of said top of said clubhead; and   e. the central extent of said increased upper concentration toward said central boundary of said toe section is less than one-half the length of said clubhead from the extreme of said toe.   
     
     
       15. The golf clubhead of claim 14 whereby: a. the length, width, and height of said increased upper concentration of mass are between about one-twentieth to one-third the length of said clubhead, one-tenth to nine-tenths the width of said clubhead, and one-twentieth to one-third the height of said clubhead; and   b. both the length and the width of said increased upper concentration are greater than the height of said increased upper concentration.   
     
     
       16. The golf clubhead of claim 15 comprising: a. an upper optimal edge approximately parallel to the width line of said clubhead positioned adjacent to said top and said toe within about one-fourth the height of said clubhead from the extreme of said top and within about one-fourth the length of said clubhead form the extreme of said toe, whereby a portion of said increased upper concentration most adjacent said top and said toe generally extends rearward along said upper optimal edge; and   b. a lower optimal edge approximately parallel to the width line of said clubhead positioned adjacent said sole and said toe within about one-fourth the height of said clubhead from the extreme of said sole and within about one-fourth the length of said clubhead from the extreme of said toe, whereby a portion of said increased lower concentration most adjacent said sole and said toe generally extends rearward along said lower optimal edge.   
     
     
       17. The golf clubhead of claim 16 whereby the loft compression ratio of said upper toe weight means is at least 1.0 and the twist compression ratio of said upper toe weight means is at least 0.70; and whereby the loft compression ratio of said lower toe weight means is at least 1.0 and the twist compression ratio of said lower toe weight means is at least 0.70. 
     
     
       18. The golf clubhead of claim 16 whereby the mass of said upper toe weight means is less than the mass of said lower toe weight means to control the vertical location of the center of mass of said clubhead. 
     
     
       19. The golf clubhead of claim 18 whereby the density of said upper toe weight means is less than the density of said lower toe weight means to control the vertical location of the center of mass of said clubhead. 
     
     
       20. The golf clubhead of claim 19 whereby the density of the material of said toe weight means is at least 11.5 grams per cubic centimeter with a content of tungsten of at least 10 percent by weight.